Solvothermal synthesis of Mn 2P 2O 7 and its application in lithium-ion battery

Abstract

Manganese pyrophosphate, Mn 2P 2O 7 was synthesized by a simple solvothermal method using Mn metal powder and P 2S 5 in ethylene glycol medium at 190–220 °C. Morphology and crystalline structure of the products were characterized by X-ray diffraction and scanning electron microscopy. The flower-like microspheres with diameters of about 2–5 μm are composed of a number of nanoplatelets with thickness of 20–40 nm. The effect of reaction temperature and reaction time on the microstructure of Mn 2P 2O 7 was investigated. The samples were used as active anode materials for lithium-ion battery and their electrochemical properties were examined by constant current charge–discharge cycling. The Mn 2P 2O 7 electrodes exhibited initial reversible capacities of 440–330 mAh g − 1 depending on the synthetic conditions. From these results, a possible reaction mechanism of Mn 2P 2O 7 with lithium was proposed.